Synthesis of Hexagonal Mesoporous Silica by Using Mixed Surfactants Liquid-Crystal as Templates.

Hexagonal mesoporous silica MCM-41 and SBA-3 were synthesized in basic or acidic medium by using mixed surfactants cetyltrimethy lammonium bromide and n-dodecylamine. X-ray diffraction and N 2 adsorption isotherm showed that the synthesized silica exhibited a well-ordered hexagonal pore structure and mesoporous pore size distributions. The effects of TMAOH/Si on the structural properties of the MCM-41 and HCl/Si on the SBA-3 were investigated. It was found that the hexagonal mesoporous silica can be formed with lower molar ratio of mixed surfactants to silica from 0.2460 to 0.264.